Metabolic diversity and synthesis of medium chain length polyhydroxyalkanoates by Pseudomonas putida LS46 cultured with biodiesel-derived by-products
| dc.contributor.author | Fu, Jilagamazhi | |
| dc.contributor.examiningcommittee | Cicek, Nazim (Biosystems Engineering) Cardona, Silvia (Microbiology) Ramsay, Juliana A. (Chemical Engineering, Queen’s University) | en_US |
| dc.contributor.supervisor | Levin, David ( Biosystems Engineering) | en_US |
| dc.date.accessioned | 2016-01-09T19:33:48Z | |
| dc.date.available | 2016-01-09T19:33:48Z | |
| dc.date.issued | 2014-06-05 | en_US |
| dc.date.issued | 2015-05-08 | en_US |
| dc.date.issued | 2015-11-06 | en_US |
| dc.degree.discipline | Biosystems Engineering | en_US |
| dc.degree.level | Doctor of Philosophy (Ph.D.) | en_US |
| dc.description.abstract | The metabolism and physiology of Pseudomonas putida strain LS46 was investigated using biodiesel-derived waste streams as potential low cost substrates for production of medium chain length polyhydroxyalkanoates (mcl-PHA). Proteomic and trranscriptomic analyses were used to correlate specific gene and gene product expression patterns with differences in phenotypes of mcl-PHA biosynthesis by P. putida LS46. Growth and mcl-PHA content of P. putida LS46 were similar in cultures containing biodiesel-derived waste glycerol versus pure glycerol, and mcl-PHA synthesis occurred during stationary phase after nitrogen concentrations in the medium were exhausted. Waste glycerol cultures contained elevated concentrations of heavy metal ions, such as copper, which induced significant changes in gene expression levels related to heavy metal resistance. Several membrane-bound proteins, such as CusABC efflux and CopAB were identified and putatively play a role in regulating cellular copper concentrations. Cultures containing waste free fatty acids synthesized mcl-PHA throughout the exponential growth phase. Protein expression levels of two mcl-PHA synthases were suppressed during exponential phase growth in waste glycerol cultures, putatively via post-transcriptional regulation. Culture specific expression of monomer supplying proteins (PhaJ1 and PhaG), and sets of fatty acid oxidation enzymes were observed, and may have contributed to differences in the composition of polymers synthesized by P. putida LS46 cultured on the two substrates. Expression levels of the majority of mcl-PHA biosynthesis pathway genes were stable during active polymer synthesis in waste glycerol cultures. However, variations in protein expression levels, and in some cases their corresponding mRNAs, were observed in a number of other metabolic patheays, such as glycerol transportation, partial glycolysis, pyruvate metabolism, the TCA cycle, and fatty acid biosynthesis. These data suggest potential regulatory points that may determine carbon flux during mcl-PHA biosynthesis. Evaluation of identified genetic targets in P. putida LS46 that putatively influence mcl-PHA biosynthesis and monomer composition merit further studies. | en_US |
| dc.description.note | February 2016 | en_US |
| dc.identifier.citation | Fu J, Sharma U, Cicek N, Sparling R, Levin DB. 2014. Evaluation of medium-chain-length polyhydroxyalkanoates production by Pseudomonas putida LS46 using biodiesel by-product streams. Canadian Journal of Microbiology 60(7): 461-468. | en_US |
| dc.identifier.citation | Fu J, Sharma PK, Spicer V, Krokhin OV, Zhang XL, Fristensky B, Wilkins JA, Cicek N, Sparling R, Levin DB. 2015. Effects of impurities in biodiesel-derived glycerol on growth and expression of heavy metal ion homeostasis genes and gene products in Pseudomonas putida LS46.” Journal of Applied Microbiology and Biotechnology. 99(13): 5583-5592. | en_US |
| dc.identifier.citation | Fu J, Sharma PK, Spicer V, Krokhin O, Zhang X, Fristensky B, Wilkins JA, Cicek N, Sparling R, Levin DB. (2015). Comparative ‘omics of Pseudomonas putida LS46 elucidates medium chain length polyhydroxyalkanoate (mcl-PHA) biosynthesis mechanisms during growth on biodiesel-derived waste streams. PLoS One 10(11): e0142322. | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/31010 | |
| dc.language.iso | eng | en_US |
| dc.publisher | Canadian Journal of Microbiology | en_US |
| dc.publisher | Journal of Applied Microbiology and Biotechnology | en_US |
| dc.publisher | PLoS One | en_US |
| dc.rights | open access | en_US |
| dc.subject | Pseudomonas putida | en_US |
| dc.subject | mcl-PHA | en_US |
| dc.subject | Biodiesel derived waste streams | en_US |
| dc.subject | Omics | en_US |
| dc.title | Metabolic diversity and synthesis of medium chain length polyhydroxyalkanoates by Pseudomonas putida LS46 cultured with biodiesel-derived by-products | en_US |
| dc.type | doctoral thesis | en_US |